The market for french fried potato strips, commonly referred to as french fries, is currently estimated at approximately 6.5-7 billion dollars annually. The bulk of this market is the fast-food restaurant business, wherein parfried and frozen potato strips are commonly purchased in bulk from commercial suppliers and stored at freezer temperatures until shortly before serving. At that point, the parfried and frozen potato strips are prepared for eating by deep fat frying in fat or oil.
McDonald's.TM. french fries, long considered the state-of-the-art in the fast-food industry, apparently are processed according to the process described in U.S. Pat. No. 3,397,993 (Strong). Therein, raw potato strips are blanched by steam or hot water until generally translucent throughout, dehydrated in hot air to cause a weight loss of at least 20 percent, parfried for 30-60 seconds at 375.degree. F. and then frozen to about 0.degree. F. The frozen potato strips are shipped and/or stored until final fry is desired. They are finish fried by immersing in a deep fat or oil bath, usually containing a medium consisting mainly of beef tallow, at a temperature of about 300.degree.-375.degree. F. for 1.5-3.5 minutes.
Another method for preparing french fries for fast food restaurants is taught in U.S. Pat. No. 3,649,305 (Wilder), wherein potato strips are dehydrated to reduce their moisture content by 10-30 percent, blanched, parfried for 30-90 seconds at about 300.degree.-400.degree. F. and then frozen. The frozen strips are then fried in oil for 1.5-3 minutes at 325.degree.-375.degree. F.
More recently, attention has been directed to the use of microwave ovens for preparing frozen french fries. In a microwave oven, high frequency energy is passed through the food product. The power absorption or specific absorption rate for a particular product depends upon a variety of physical and chemical factors, such as frequency, product temperature, the magnitude of the electric field in the product, density and dielectric constants. The high frequency energy excites polar molecules (such as water) contained within the food product and heat is generated as a result.
Various references disclose methods for preparing french fried potato products which can be cooked in microwave ovens.
U.S. Pat. No. 4,456,624 (Glantz et al.) discloses embedding potato pieces in potato strips by high energy impingement which disrupts the surface which has been preheated in water. Thereafter, the strips are blanched and parfried for 5-20 seconds at 340.degree.-380.degree. F. After freezing, the potato strips are either fried or oven baked to complete the process. The patent also states that the potato strips also may be finally cooked in a microwave oven, although no examples are provided.
U.S. Pat. No. 4,590,080 (Pinegar) discloses subjecting potato strips to blanching, parfrying for 50-100 seconds at 360.degree. F., intermediate freezing at -40.degree. F. for 10 minutes, a longer parfrying for 2-4 minutes at 360.degree. F., blast freezing, storing and microwaving.
U.S. Pat. No. 4,109,020 (Gorfien et al.) discloses partially dehydrating frozen parfried potato strips by heating in an air oven or by heating in a combination microwave/air oven and then additionally heating in an air oven, frying in a deep fat fryer for 1 to 3 minutes at 375.degree. F., freezing at -10.degree. F. for 4 hours, storing and microwaving.
Finally, U.S. Pat. No. 4,219,575 (Saunders et al.) discloses a complex sinusoidal strip surface configuration for crinkle cut potatoes which are subjected to frying for 4 minutes at 350.degree. F., and thereafter blast frozen to an internal temperature of 0.degree. F. A two ounce sample of these crinkle-cut potatoes may be reheated in a microwave oven for one minute at 1000 watts.
It is therefore an object of the present invention to provide a french fried product which upon reheating in a microwave oven to a suitable temperature for consumption closely resembles the flavor, aroma, texture, mouthfeel and total eating experience of a deep-fat fried fast food french fry.
It is another object of the present invention to provide a microwaveable french fried potato product which can be microwaved in a convenience store or in the consumer's home in a very short period of time, which is highly palatable and has a crisp exterior and tender interior.